A Long Term Evolution (LTE) system typically allocates scheduling resources by dynamic scheduling way, but control information needs to be set for each service transmission so as to allocate resources using dynamic scheduling, as users simultaneously accessing a same cell increase progressively, control information desired to implement dynamic scheduling, which needs to be transmitted in the LTE system, also increases progressively, thereby affecting severely communication performances over air interfaces of the LTE system.
Therefore, in order to solve the problem of progressively increasing control information, for voice/data services having a fixedly-sized data packet and an arrival time interval meeting a certain law, for example Voice over Internet Protocol (VoIP) services, resources are allocated using a Semi-Persistent Scheduling (SPS) way.
The SPS refers to a scheduling way in which an Evolved Node B (eNB) transmits in advance control information for SPS to a UE, then the control information is not desired to be transmitted any longer, the UE can transmit and receive air interface data periodically according to time-frequency resources in Downlink Control Information (DCI) and the control information transmitted from the eNB, in this way, the overheads of control information can be reduced to avoid influence of excessive control information on communication performances over air interfaces of the LTE system.
FIG. 1 shows hierarchical relations of protocol stacks for control planes among a UE, an eNB and an Evolved Packet Core (EPC) in an LTE system, as shown in FIG. 1, the UE includes a Non-Access Stratum (NAS) and an Access Stratum (AS), wherein the AS includes a Physical layer (PHY) entity, a Medium Access Control (MAC) entity, a Radio Link Control (RLC) entity, a Packet Data Convergence Protocol (PDCP) entity and a Radio Resource Control (RRC) entity; the eNB includes a PHY entity, an MAC entity, an RLC entity, a PDCP entity and an RRC entity corresponding to respective entities of the AS of the UE; and the EPC includes an NAS corresponding to the NAS of the UE.
FIG. 2 is a schematic diagram showing Logic Channels (LCs) and Logic Channel Groups (LCGs) between an MAC entity and an RLC entity of a UE. There are totally 11 LCs for transmitting uplink/downlink signaling and services between the MAC entity and the RLC entity, the 11 LCs are divided into 4 LCGs, each LCG can include 4 LCs at the most. The LC is identified by a Radio Bearer Identity (RBID), and each LC corresponds to one RBID. The MAC entity is used to schedule services allocated to logic channels by classifiers.
At present, establishing a bearer supporting uplink SPS includes: an Evolved Packet System (EPS) bearer is established between an NAS of a UE and an NAS of an EPC, logic channels and logic channel groups that support uplink SPS are established respectively between an MAC entity and an RLC entity of the UE and between an MAC entity and an RLC entity of an eNB, and a corresponding relationship between respective classifiers and respective logic channels supporting uplink SPS is established. In this way, the establishment of a bearer supporting uplink SPS is completed, and the classifiers are used to allocate the received uplink services to corresponding logic channels.
According to regulations of the LTE protocol, an RRC entity of a UE can only transmit EPS bearer activation request information to the NAS entity, but cannot be an MAC entity of an AS, then the MAC entity cannot acquire the Quality of Service Class Identifier (QCI) included in the EPS bearer activation request information. The QCI is used to identify uplink services suitable for SPS. This will result in problems that the MAC entity doesn't know which services of uplink services allocated to logic channels are adapted to be scheduled using SPS, then the MAC entity may schedule uplink service which is more fit for SPS scheduling, by using dynamic scheduling, thus quality of uplink service scheduling is affected and resources reserved by the eNB and EPC for uplink SPS are wasted.